iWorld is not available for 1.1.3 yet, if you are looking to upgrade to 1.1.3 be aware the international support is limited to these counties, even then there is no garantee you Service provider/language is fully supported:

yes if your country is listed above you can set it up to work out of the box. No need for iworld
And yes some european countries are supported more than once if there are different language populations

Well, we'll see soon whether it really works in Switzerland... I just found this article over a iclarified (http://www.iclarified.com/entry/index.php?enid=684) which explains how to patch AppSupport under 1.1.3 in order to avoid crashes when dialing a number.

So I will see whether I need this or not...

Sargon

PS. Ok, restored and used ZiPhone 2.3 (under Tiger!) and everything's working fine

you have to choose between either German or French speaking...
My phone is however set up in English, so it really looks odd to me, when the weather and time are shown in either German or French (depending on the language I chose)...

There are a couple of patches that you can apply here that will work for nearly everywhere an iPhone would crash when calling. The all around easiest patch is timschuerewegen's AppSupport Patch which will fix any region on iWorld and more. You can download this in installer. Go to the "Sources" then download Bigboss's Beta/Experimental and beta source repository. Once you do this go to the Tweeks (1.1.[34]) depending on which one you have and install timschuerewegen's AppSupport Patch.

If you would also like to change the language and keyboard settings as well add the source repo.aakqtr.com (also known as BiOsS's Mods) and download a package called "*1.1.[34]* International Support" again depending on whether you have 1.1.3 or 1.1.4. There are over 20 different languages/keyboards to choose from.